This invention relates to magnetic tape cassettes. In particular, it relates to a small video cassette in which a reel retainer depresses the tops of a pair of reel hubs to urge each hub in its axial direction, so that rotating centers are maintained when the tape is run.
Such a reel retaining plate when used in an ordinary size video cassette suitably depresses the centers of the upper surfaces of the reel hubs in order to smoothly rotate the reel hubs and satisfactorily run the tape. This improves the picture recording and reproducing characteristic of the cassette unit. The reel retaining plate is mounted on the upper cassette half (hereinafter referred to as "the upper half", when applicable). The reel retaining plate is curved in the direction of depression, or the hub top contacting parts of the reel retaining plate are partially bent, so that the end parts thereof lightly depress the tops of the reel hubs.
FIG. 1 shows a conventional reel retaining plate 3 of this type. The reel retaining plate 3 is supported according to a cantilever system as shown in FIG. 1. Therefore, the plate 3 should be rigidly mounted on the upper half. In FIG. 1, the plate 3 is fixedly secured to the upper half 1 at two points 7. If the plate 3 is not positively secured to the upper half 1, then, it is liable to have play associated with it and as a result, its ends 11 cannot uniformly depress the reel hubs. In this case, the tape will not smoothly run; i.e., the picture recording and reproducing characteristic is lowered. This drawback is significant in the case of a small video cassette, because its reel-retaining-plate mounting space is small. Thus, it is essential to improve the technique of mounting the reel retaining plate.